Drug delivery in pluronic micelles: effect of high-frequency ultrasound on drug release from micelles and intracellular uptake.

The effect of high-frequency ultrasound on doxorubicin (DOX) release from Pluronic micelles and intracellular DOX uptake was studied for promyelocytic leukemia HL-60 cells, ovarian carcinoma drug-sensitive and multidrug-resistant (MDR) cells (A2780 and A2780/ADR, respectively), and breast cancer MCF-7 cells. Cavitation events initiated by high-frequency ultrasound were recorded by radical trapping. The onset of transient cavitation and DOX release from micelles were observed at much higher power densities than at low-frequency ultrasound (20-100 kHz). Even a short (15-30 s) exposure to high-frequency ultrasound significantly enhanced the intracellular DOX uptake from PBS, RPMI 1640, and Pluronic micelles. The mechanisms of the observed effects are discussed.     

次声对HL-60白血病细胞株生长的影响

目的：探讨次声治疗仪对HL-60人白血病细胞株生长的影响。方法：采用次声治疗仪发生的相同强度（档位3）不同作用时间的次声直接作用于离体培养的HL-60细胞（作用组），对照组细胞暴露在空气中，分别在实验处理的15min、30min、60min、90min和120min取样检测，以台盼蓝活细胞计数，MTT比色法及流式细胞仪技术，观察比较HL-60细胞的生长情况。结果i不同次声作用时间对HL-60细胞生长影响的差异不具显著性意义（p〉0．05）。结论：治疗剂量的次声处理对HL-60细胞的生长无明显影响。     

PHⅡ-7增强阿霉素杀伤HL-60/ADR细胞的作用及机制研究

目的 研究PH Ⅱ-7增强阿霉素杀伤HL-60/ADR细胞的作用及其相关机制.方法 用MTT法测定阿霉素、PHⅡ-7单独及联合用药对阿霉素杀伤人急性髓系白血病耐药细胞株(HL-60/ADR)及其亲代细胞系(HL-60)作用的IC50值,提取不同浓度PH Ⅱ-7处理不同时间后HL-60和HL-60/ADR细胞的RNA,RT-PCR法分析PHⅡ-7对MRP基因表达水平的影响,通过激光共聚焦显微镜和流式细胞术观察PHⅡ-7处理前后HL-60和HL-60/ADR细胞内阿霉素浓度的改变.结果 PH Ⅱ-7本身具有抗肿瘤活性,对HL-60和HL-60/ADR的IC50值分别为(0.83±0.08)μmol/L,(1.74±0.56)μmol/L.PHⅡ-7还能协同提高阿霉素的细胞毒作用,HL-60组两药相互作用指数(CDI)值为0.7,HL-60/ADR组CDI值为0.43,其对耐药细胞的协同作用更为显著.随PHⅡ-7作用时间延长及剂量增加,细胞MRP基因表达水平逐渐下降,细胞内阿霉素浓度逐渐提高,可达敏感细胞的55%.结论 PHⅡ-7是有效的肿瘤细胞化疗药物,还具有下调MRP耐药基因表达的作用,从而有效逆转HL-60/ADR细胞的耐药现象,协同增强化疗药物对细胞的杀伤作用.     

硼替佐米对多药耐药HL-60细胞增殖的影响及耐药逆转作用

目的 观察硼替佐米对多药耐药白血病细胞增殖的影响及耐药逆转作用,初步探讨硼替佐米抑制多药耐药白血细胞增殖的分子机制.方法 以多药耐药白血病细胞系HL-60/DNR和HL-60/VCR细胞为模型,以HL-60细胞为对照,用四甲基偶氮唑盐反应比色法(MTT法)测定硼替佐米对HL-60、HL-60/DNR和HL-60/VCR细胞增殖的抑制作用,计算微毒剂量作为逆转耐药剂量.分4个实验组:HL-60/DNR+柔红霉素(DNR)、HL60/DNR+DNR+硼替佐米、HL-60/VCR+长春新碱(VCR)、HL-60/VCR +VCR+硼替佐米,计算硼替佐米逆转耐药倍数.硼替佐米按浓度递增(10、40、80nmol/L)作用于HL-60/DNR和HL-60/VCR细胞48 h,实时定量RT-PCR和Western blot方法检测XIAP、cIAP-1、cIAP-2 mRNA和蛋白表达水平及NF-κB活性.结果 硼替佐米呈浓度依赖性抑制HL-60、HL-60/DNR和HL-60/VCR细胞增殖,IC50值分别为(28.90 ±3.99)、(81.19 ±9.34)和(73.48±8.94) nmol/L.10 nmol/L硼替佐米预处理48 h后,DNR对HL-60/DNR细胞的IC50值由(12.90±1.75) μmol/L降低至(3.54±0.57) μmol/L(P ＜0.01),VCR对HL-60/VCR的IC50值由(33.25 ±7.28)μmol/L降低至(9.97±1.15) μmol/L(P ＜0.01),逆转耐药倍数分别为(3.32±0.53)和(2.64±0.28)倍.硼替佐米呈浓度依赖性下调XIAP、cIAP-1、cIAP-2 mRNA和蛋白的表达水平及抑制NF-κB活化.结论 硼替佐米可抑制多药耐药HL-60细胞增殖,并对多药耐药具有一定的逆转作用;其机制可能与下调凋亡抑制蛋白表达相关.     

Acoustic activation of drug delivery from polymeric micelles: effect of pulsed ultrasound.

The effect of a continuous wave (CW) and pulsed 20-kHz ultrasound on the Doxorubicin (DOX) uptake by HL-60 cells from the phosphate buffered saline solution (PBS) and Pluronic micellar solutions was studied. Both CW and pulsed ultrasound enhanced DOX uptake from PBS and Pluronic micelles. The main factor that effected drug uptake was ultrasound power density; however, with increasing power, the enhanced drug uptake was accompanied by the extensive cell sonolysis. For PBS, no significant effect of duration of the ultrasound pulse or inter-pulse interval on the drug uptake was observed. For Pluronic micelles, the uptake increased with increasing pulse duration in the range 0.1-2 s, overall sonication time being the same. For 2-s pulses, the uptake was close to that under CW ultrasound. There was no significant effect of the duration of the inter-pulse interval on the drug uptake from Pluronic micelles. The data on the effect of pulse duration on drug uptake suggest that the characteristic times of drug release from micelles and drug uptake by the cells are comparable. The results point to two independent mechanisms controlling acoustic activation of drug uptake from Pluronic micelles. Both mechanisms work in concert. The first one is related to the acoustically-triggered drug release from micelles that results in higher concentration of the free drug in the incubation medium. The second mechanism is based on the perturbation of cell membranes that results in the increased uptake of the micellar-encapsulated drug. The intracellular uptake of Pluronic micelles was confirmed by fluorescence microscopy.     

Effect of ultrasound on transdermal drug delivery to rats and guinea pigs.

The effect of therapeutic range ultrasound (1 MHz) on skin permeation of D-mannitol, a highly polar sugar alcohol, inulin, a high molecular weight polysaccharide and physostigmine, a lipophilic anticholinesterase drug was studied in rats and guinea pigs. D-Mannitol and inulin are totally and rapidly excreted, once they have penetrated through the skin into the blood stream, permitting direct in vivo monitoring. For evaluating skin penetration of physostigmine the decrease of whole blood cholinesterase was measured. Ultrasound nearly completely eliminated the lag time usually associated with transdermal delivery of drugs. 3-5 min of ultrasound irradiation (1.5 W/cm2 continuous wave or 3 W/cm2 pulsed wave) increased the transdermal permeation of inulin and mannitol in rats by 5-20-fold within 1-2 h following ultrasound application. Ultrasound treatment also significantly increased (P less than 0.05) the inhibition of cholinesterase during the first hour after application in both physostigmine treated rats and guinea pigs: while in control guinea pigs no significant inhibition of cholinesterase could be detected during the first 2 h after application of physostigmine, the ultrasound treated group showed a 15 +/- 5% (mean +/- SEM) decrease in blood cholinesterase 1 h after ultrasound application. For physostigmine-treated rats the level of cholinesterase inhibition 1 h after ultrasound application was 53 +/- 5% in the ultrasound-treated group and 35 +/- 5% in the controls.     

In vitro study of the apoptosis effect of DNR on HL-60 cells and its relationship with ROS, CER and NF-kappaB]

OBJECTIVE: To study the effect of DNR on HL-60 cells apoptosis in vitro and the related mechanism. METHODS: The apoptosis of HL-60 was observed by microscope, flow cytometry (FCM) and DNA electrophoresis and various apoptosis-associated proteins expression by immunocytochemistry (IC) and FCM assays; the changes of apoptosis in HL-60 cells treated with DNR or suppressors PDTC or FB1 were also observed. RESULTS: When treated with 0.2 approximately 2.0 micro mol/L DNR, the percentage of apoptotic HL-60 cells increased with the dose increasing and the time extending, and the typical apoptotic cells and the appearance of apoptotic DNA ladder were observed. It was shown that after treatment with 1 micro mol/L DNR, the fluorescence intensity index (FI) of both bcl-2 and c-myc in HL-60 cells decreased, the FI of Bax, caspase-3 increased at 2 h, but decreased at 5 h, the FI of NF-kappaB increased. After adding PDTC, the apoptosis percentage of HL-60 cells decreased, but FB1 didn't present these effect. CONCLUSION: It suggested from the results that at certain concentration, DNR can induce the apoptosis of HL-60 cells in vitro. The mechanism was supposed by suppressing the expression of bcl-2 and c-myc and activating the expression of Bax and caspase-3, NF-kappaB and ROS had the marked correlation with the apoptosis process, but the ceramide synthase wasn't associated with it.     

柔红霉素对HL-60细胞的促凋亡作用及其与ROS、CER、NF-κB关系的实验研究

目的：探讨柔红霉素（DNR）在体外作用于HL－60细胞时细胞发生凋亡的规律及一些相关机制。方法：应用光镜、流式细胞仪（FCM）及DNA电泳检测DNR诱导HL－60细胞的凋亡作用；用免疫细胞化学（IC）、FCM观察相关蛋白的变化。加入活性氧（ROS）抑制剂四氢吡咯烷二硫氨基甲酸酯（PDTC）或神经酰胺（CER）合成酶抑制剂马廉菌素B1（FB1）后，观察DNR诱导的HL－60细胞凋亡率的变化。结果：当DNR浓度为0．2－2．0μmol/L时，HL－60细胞发生的凋亡率随药物浓度的增加与作用时间的延长而升高，可见典型的凋亡细胞及明显的DNA梯度条带。当1．0μmol/L DNR作用于HL－60细胞后，细胞中Bcl-2与C－myc蛋白的荧光强度指数（FI)总的趋势降低，Bax、caspase-3的FI值在作用2h时上升，而5h时降低，核因子κB（NF-κB）的FI值持续升高。PDTC可抑制DNR对HL－60细胞的凋亡诱导作用，而FB1无影响。结论：一定浓度的DNR在体外诱导HL－60细胞凋亡，发生凋亡的机制可能是通过抑制Bcl-2和C－myc蛋白的表达、激活Bax、caspase-3蛋白诱导的；此凋亡过程与ROS、NF－κB有关，而与CER合成酶无关。     

Micellar formulations for drug delivery based on mixtures of hydrophobic and hydrophilic Pluronic block copolymers.

Micelles formed by Pluronic block copolymers (PBC) have been studied in multiple applications as drug delivery systems. Hydrophobic PBC form lamellar aggregates with a higher solubilization capacity than spherical micelles formed by hydrophilic PBC. However, they also have a larger size and low stability. To overcome these limitations, binary mixtures from hydrophobic PBC (L121, L101, L81, and L61) and hydrophilic PBC (F127, P105, F87, P85, and F68) were prepared. In most cases, PBC mixtures were not stable, revealing formation of large aggregates and phase separation within 1-2 day(s). However, stable aqueous dispersions of the particles were obtained upon (1). sonication of the PBC mixtures for 1 or 2 min or (2). heating at 70 degrees C for 30 min. Among all combinations, L121/F127 mixtures (1:1% weight ratio) formed stable dispersions with a small particle size. The solubilizing capacity of this system was examined using a model water-insoluble dye, Sudan (III). Mixed L121/F127 aggregates exhibited approximately 10-fold higher solubilization capacity compared to that of F127 micelles. In conclusion, stable aqueous dispersions of nanoscale size were prepared from mixtures of hydrophobic and hydrophilic PBC by using the external input of energy. The prepared mixed aggregates can efficiently incorporate hydrophobic compounds.     

Effect of Embelin on proliferation, differentiation and aopotosis of HL-60 cells

OBJECTIVE: To study the effect of embelin on proliferation, differentiation and apoptosis of HL-60 cells and explore its possible mechanism. METHODS: Different concentration of embelin were used to treat HL-60 cells. Cell growth curve was analysed by MTT assay, cell apoptosis by Annexin V/PI double staining and JC-1 dye. The differentiation of HL-60 cells was evaluated by expression of CD33, CD34, CD11b and CD14. Bone marrow cells (BMC) from nine patients with acute nonlymphocytic leukemia (ANML) were also studied. RESULTS: Embelin induced differentiation of HL-60 cells with significant increase of CD14 and CD11b expression at 33.97μmol/L for 3 days (P < 0.01). Embelin induced apoptosis of HL-60 cells in a time- and dose-dependent manner, the apoptosis rates were (9.23 ± 0.05)%, (25.86 ± 0.30)% and (39.03 ± 0.07)% respectively at 339.67 μmol/L of embelin for 12-, 24- and 48-hours treatment (P < 0.05); the apoptosis rates were (0.07 ± 0.03)%, (7.43 ± 0.30)%, (14.01 ± 0.01)%, (25.52 ± 0.03)% and (39.15 ± 0.01)% respectively at 10.19, 33.97, 101.90, 339.67 and 1019.02 μmol/L of embelin for 24-hours culture (P < 0.05). Clusters of differentiation antigen on BMC from three acute promyelocytic leukemia patients showed significant changes at 33.97 μmol/L of embelin treatment for 3 days. Embelin induced apoptosis of BMCs from all the nine ANML patients at 33.97 μmol/L for 24 hour. CONCLUSION: Embelin can inhibit proliferation and induce differentiation and apoptosis of HL-60 cells. The mechanism may be related to mitochondrial apoptosis pathway. Embelin at subtoxic concentration doesn't promote leukemia BMC differentiation, but at 339.67 μmol/L induces apoptosis of these cells.     

Embelin对HL-60细胞增殖、分化和凋亡的影响

目的 研究Embelin对HL-60细胞增殖、分化和凋亡的影响,并对其作用机制进行初步探讨.方法 用不同浓度的Embelin处理HL-60细胞,采用MTT法绘制生长曲线,通过Annexin V/PI 复染及JC-1染色,观察Embelin对HL-60细胞凋亡的影响;通过流式细胞术检测细胞表面分化抗原CD33、CD34、CD11b和CD14表达的变化.在对HL-60细胞研究的基础上,选择9例急性非淋巴细胞白血病(ANLL)患者的骨髓进行相应的研究.结果 Embelin对HL-60细胞具有增殖抑制作用,且作用呈时间和剂量依赖性.24 h的,IC50值为429.98 μmoL/L.33.97 μmol/L的Embelin作用HL-60细胞3 d,流式细胞术检测结果 显示CD11b、CD14阳性细胞率均升高(P值均<0.01);339.67 μmol/L Embelin作用于HL-60细胞后12、24及48 h的特异性凋亡率分别为(9.23 ±0.05)%、(25.86 ±0.30)%和(39.03±0.07)%,10.19、33.97、101.90、339.67及1019.02 μmol/L Embelin作用于HL-60细胞24 h后特异性凋亡率分别为(0.07±0.03)%、(7.43±0.30)%、(14.01±0.01)%、(25.52±0.03)%和(39.15±0.01)%,其诱导凋亡的作用呈时间及剂量依赖性.33.97 μmol/L的Embelin作用于ANLL 患者骨髓细胞3 d,3例M3患者骨髓细胞表面分化抗原出现显著性改变;339.67 μmol/L的Embelin作用患者骨髓细胞24 h,9例均发生凋亡.结论 亚细胞毒浓度的Embelin可诱导HL-60细胞向单核细胞分化;高浓度的Embelin对HL-60细胞具有增殖抑制及促进凋亡的作用.其促进凋亡的机制与线粒体凋亡途径有关.亚细胞毒浓度的Embelin对体外培养的M3患者骨髓细胞具有促进分化的作用;339.67 μmol/L的Embelin对ANLL骨髓细胞具有促进凋亡的作用.     

大萼香茶菜甲素对HL-60细胞增殖、分化和凋亡的影响

目的 探讨大萼香茶菜甲素(macrocalyxin A,MA)对白血病细胞系HL-60细胞增殖、分化和凋亡的影响,并对其作用机制进行初步探讨.方法 用不同浓度的MA处理HL-60细胞,锥虫蓝染色、MTT比色法观察对HL-60细胞增殖的影响;以细胞形态学、DNA含量及细胞周期分析、Annex-in-V/PI双标记和Hoechst 33258荧光染色等分析细胞凋亡;通过细胞表面抗原CD11b、CD13、CD14,NBT试验和细胞形态学检测MA诱导HL-60细胞的分化作用;用流式细胞术检测Bcl-2、Bax、P53、Fas表达和线粒体膜蛋白、线粒体跨膜电位(△Ψm)的变化.结果 HL-60细胞经MA作用后,MA呈时效及量效性地抑制HL-60细胞增殖,24、48、72 h的IC50值分别为8.76、7.17、7.14μg/ml;形态学出现典型的凋亡细胞特征,亚G1期细胞和Annexin-V/PI标记阳性细胞显著升高;细胞发生部分分化,CD11b表达增加,NBT阳性细胞增多;MA诱导HL-60细胞凋亡和分化过程中,Bcl-2、Fas、P53表达无明显变化,Bax、线粒体膜蛋白表达显著增加,Bax/Bcl-2比值升高,线粒体膜电位(△Ψm)下降.结论 MA能抑制HL-60细胞增殖、诱导HL-60细胞向粒系分化、促进细胞凋亡,其机制与上调bax基因和bax/bcl-2比值、提高线粒体膜通透件和下调线粒体膜电位等有关.     

Bacterial ghosts as novel advanced drug delivery systems: antiproliferative activity of loaded doxorubicin in human Caco-2 cells.

Systemic application of anticancer drugs often causes severe toxic side effects. To reduce the undesired effects, advanced drug delivery systems are needed which are based on specific cell targeting vehicles. In this study, bacterial ghosts from Mannheimia haemolytica were used for site-specific delivery of doxorubicin (DOX) to human colorectal adenocarcinoma cells (Caco-2). Bacterial ghosts are non-denatured envelopes of Gram-negative bacteria with fully intact surface structures for specific attachment to mammalian cells. The in vitro release profile of DOX-ghosts demonstrated that the loaded drug was non-covalently associated with the bacterial ghosts and that the drug delivery vehicles themselves represent a slow release system. Adherence studies showed that the M. haemolytica ghosts more efficiently than E. coli ghosts targeted the Caco-2 cells and released the loaded DOX within the cells. Cytotoxicity assays revealed that the DOX-ghosts exhibited potent antiproliferative activities on Caco-2 cells as the DOX associated with ghosts was two magnitude of orders more cytotoxic than free DOX provided in the medium at the same concentrations. Notably, a significant reduction in the cell viability was measured with DOX-ghosts at low DOX concentrations, which had no inhibitory effect when applied as free DOX after incubation for 16 h or when applied at higher concentrations for only 10 min to the cells. As the higher antiproliferative effects of DOX on Caco-2 cells were mediated by the specific drug targeting properties of the bacterial ghosts, the bacterial ghost system represents a novel platform for advanced drug delivery.     

mPGES-1抑制剂MK886对白血病HL-60/A细胞凋亡及耐药性的影响

为了探讨膜结合型前列腺素E2合酶1(mPGES-1)抑制剂MK886对耐药白血病HL-60/A细胞诱导凋亡的作用及对其耐药性的影响,采用QT-PCR及Western blot法检测HL-60/A细胞mPGES-1的表达,CCK-8法观察药物对HL-60/A细胞增殖的影响,流式细胞术检测细胞凋亡,ELISA法检测PGE2的合成,Western blot法检测Akt、P-Akt表达,并观察低浓度(10μmol/L)MK886对HL-60/A细胞耐药性及多药耐药基因表达的影响。结果表明,HL-60/A细胞高表达mPGES-1,MK886可时间、浓度依赖性地抑制HL-60/A细胞增殖,诱导其凋亡(r=-0.83,P<0.05),同时,mPGES-1表达及PGE2合成减少,P-Akt表达明显下降。低浓度MK886可下调多药耐药基因mdr-1及蛋白P170表达,增强对化疗的敏感性。结论:MK886可抑制耐药白血病HL-60/A细胞增殖,诱导其凋亡,增强其化疗敏感性,其机制与下调mPGES-1/PGE2合成、抑制P-Akt蛋白及多药耐药基因表达有关。     

六亚甲基二乙酰胺对急性白血病细胞株HL-60和U937分化、凋亡的影响及其机制

目的　研究六亚甲基二乙酰胺 (HMBA)体外诱导HL 6 0和U937细胞分化、凋亡的作用及其机制。方法　流式细胞仪检测细胞分化抗原CD1 1b、CD1 4,细胞凋亡标记Annexin Ⅴ以及进行细胞周期分布和细胞内cyclinD、cyclinE、p2 7抗原的分析 ,RT PCR检测c myc、Rb、Bcl 2基因mRNA的表达。结果　HL 6 0、U937细胞经HMBA处理 72h后CD1 1b表达显著增高 ,高剂量HMBA促使Annexin Ⅴ表达增加。HMBA阻滞HL 6 0、U937细胞于G0 G1 期 ,并使该两种细胞内cyclinE表达显著下降 ,cyclinD、p2 7表达显著增高 ,呈剂量依赖关系 ;HMBA可使HL 6 0、U937细胞c myc、Bcl 2mRNA表达下调 ,而RbmRNA在HL 6 0细胞表达上调 ,在U937细胞则无显著改变。结论　HMBA能诱导HL 6 0、U937细胞出现明显的分化 ,高剂量的HMBA有促使HL 6 0、U937细胞凋亡的倾向 ,其机制可能是通过影响细胞周期调控分子以及有关的增殖分化相关基因的表达 ,从而抑制细胞增殖 ,促进细胞分化。     

Micellar carriers based on block copolymers of poly(epsilon-caprolactone) and poly(ethylene glycol) for doxorubicin delivery.

Diblock copolymers of poly(epsilon-caprolactone) (PCL) and monomethoxy poly(ethylene glycol) (MPEG) with various compositions were synthesized. The amphiphilic block copolymers self-assembled into nanoscopic micelles and their hydrophobic cores encapsulated doxorubicin (DOX) in aqueous solutions. The micelle diameter increased from 22.9 to 104.9 nm with the increasing PCL block length (2.5-24.7 kDa) in the copolymer composition. Hemolytic studies showed that free DOX caused 11% hemolysis at 200 microg ml(-1), while no hemolysis was detected with DOX-loaded micelles at the same drug concentration. An in vitro study at 37 degrees C demonstrated that DOX-release from micelles at pH 5.0 was much faster than that at pH 7.4. Confocal laser scanning microscopy (CLSM) demonstrated that DOX-loaded micelles accumulated mostly in cytoplasm instead of cell nuclei, in contrast to free DOX. Consistent with the in vitro release and CLSM results, a cytotoxicity study demonstrated that DOX-loaded micelles exhibited time-delayed cytotoxicity in human MCF-7 breast cancer cells.     

DNA损伤时钠氢交换蛋白1在K562和HL-60细胞中的表达和对细胞凋亡的影响

本研究主要探讨在依托泊苷引起的DNA损伤下,BCR-ABL阳性细胞系K562中钠氢交换蛋白-1(NHE1)的表达变化情况,并初步探讨其在何种水平被调控。采用实时定量PCR技术检测NHE1在mRNA水平的表达;Western blot检测依托泊苷对细胞NHE1在蛋白水平的影响;流式细胞术测定细胞凋亡情况;构建NHE1启动子区荧光素酶报告载体,并测定不同依托泊苷浓度作用下的荧光素酶活性。结果表明:DNA损伤引起HL-60细胞NHE1在mRNA和蛋白水平升高(p<0.05),在K562细胞中未发现明显变化(p>0.05);依托泊苷对HL-60细胞有明显的促凋亡作用,阻止细胞内pH值的升高可以降低依托泊苷的促凋亡作用,依托泊苷对K562细胞凋亡率无明显影响;K562细胞在DNA损伤时,NHE1启动子区构建的荧光素酶表达载体活性升高。结论:依托泊苷造成的DNA损伤,促进HL-60细胞凋亡,并且依赖pHi的改变;在K562细胞中NHE1表达没有改变,但其转录活性升高。     

细胞内酸化逆转HL-60、MSC和脐血CD34~+细胞耐药的研究

本研究主要探讨细胞酸化对罗丹明123(rhodamine Rh123)在不表达或低表达MDR1且分化程度较低的细胞中累积的影响,为抗白血病细胞多药耐药(multidrug resistance,MDR)寻找胞内酸化逆转的新方法。采用实时定量PCR技术检测MDR1基因在mRNA水平的表达;利用高钾缓冲液对细胞进行酸化,应用激光共聚焦显微镜测定HL-60、MSC及CD34+脐血细胞pHi值;采用MTT法观察细胞酸化对细胞活力的影响;应用流式细胞术检测细胞酸化对HL-60、MSC及脐血CD34+细胞内Rh123累积的影响。结果表明:细胞酸化3小时对HL-60、MSC及脐血CD34+细胞的活力无明显影响,细胞酸化能明显改变细胞对Rh123的累积;此外,细胞分化程度越低,其细胞内Rh123的累积越少。结论 :细胞酸化能逆转HL-60、MSC和脐血CD34+细胞的耐药。